1. Field of the Invention
The present invention relates to a container for a liquid, and more specifically, to a container for a liquid which is suitable for use as a container for a processing solution which is used in developing processing of a photosensitive material.
2. Description of the Prior Art
Photosensitive material processing apparatuses such as automatic developing apparatuses have used rigid containers for liquids which are formed by blow molding or injection blow molding and by using a single-layer material such as high density polyethylene (HDPE), polyvinylchloride resin (PVC) or polyethylene terephthalate (PET) or a multi-layer material such as nylon/polyethylene (NY/PE). These materials are used as they are suitable for the self-supportability of the container (i.e., the ability of the container to stand alone without external support) and because they are suitable for the filling of the container with liquid at a factory and for the pouring of the liquid into a processing tank, thereby facilitating use of the container. Further, these materials are used because they guarantee the strength required by UN regulations (regulations for the transport of exported dangerous substances, i.e., legal regulations considering the drop strength at -18.degree. C.) as well as regulations for poisonous substances.
However, even when the contents of such a conventional, rigid container for a liquid have been discharged and the container is empty, the container retains its configuration due to the rigidity thereof. Therefore, it is difficult for a user to crush the container after the container has been used and is to be discarded. A drawback arises in that the used containers occupy a relatively large amount of space.
Recently, blow-molded containers have been developed in which a bellows portion is provided at a trunk portion of the container so that the container can be collapsed by being pressed. In accordance with such collapsible, blow-molded containers, the collapsed state can be maintained by tightly closing a cap when the container is collapsed. Therefore, the collection efficiency improves when the containers are collected with the caps fastened thereto.
However, with such conventional blow-molded containers, there is a drawback in that it is easy for the container to return to its original configuration when the cap is removed therefrom.
in recent years, as more consideration has been given to using limited natural resources more efficiently, blow-molded containers have been reused as material for resin manufactured products. When used containers are collected for reuse, it is usually necessary to separately collect the cap and the container, which are formed of different resin materials, but deterioration of the collection efficiency should be kept to a minimum. In order to achieve this object of efficient reuse, the inventors of the present invention have trial manufactured various types of containers having bellows portions of various cross sectional configurations, and have found that it is difficult for a gradually-widening container, which has a bellows portion with a circular cross section and in which the diameter of the bellows portions gradually increases from top to bottom, to return to its original configuration.
In the case of containers for photographic processing solutions, a plurality of containers for processing solutions which are filled with the same type of processing solution are packed in a corrugated fiberboard box or the like, or containers for processing solutions which are filled with different types of processing solutions such as developing solution, fixing solution, bleaching solution and the like are packed in the same corrugated fiberboard box, and are shipped from the manufacturer and distributed. However, when the above-described circular, gradually-widening containers are packed in boxes, a drawback arises in that there is wasted space between the containers and the packing efficiency is insufficient.